Second-half goals from Lucas Piazon and Denis Odoi took Fulham through to the second round of the Carabao Cup.
Piazon opened the scoring with a brilliant strike in the 67th minute, finding the top corner after being found by Cauley Woodrow.
Woodrow and Wycombe’s Paul Hayes had earlier missed chances to break the deadlock.
Odoi’s header from Piazon’s 81st-minute corner sealed the victory for Slavisa Jokanovic’s side.
Fulham keeper Marek Rodák produced a fine save in stoppage time to keep out Nathan Tyson’s header.